HTTP2: Initiate write for acknowledging SETTINGS frame (#29218)

* HTTP2: Initiate write for acknowledging SETTINGS frame

* Codegen

* yapf code

* Fix tests

src/core/ext/transport/chttp2/transport/chttp2_transport.cc

@@ -852,6 +852,9 @@ static void inc_initiate_write_reason(
     case GRPC_CHTTP2_INITIATE_WRITE_SEND_SETTINGS:
       GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_SEND_SETTINGS();
       break;
+    case GRPC_CHTTP2_INITIATE_WRITE_SETTINGS_ACK:
+      GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_SETTINGS_ACK();
+      break;
     case GRPC_CHTTP2_INITIATE_WRITE_FLOW_CONTROL_UNSTALLED_BY_SETTING:
       GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_FLOW_CONTROL_UNSTALLED_BY_SETTING();
       break;
@@ -3300,6 +3303,8 @@ const char* grpc_chttp2_initiate_write_reason_string(
       return "TRANSPORT_FLOW_CONTROL";
     case GRPC_CHTTP2_INITIATE_WRITE_SEND_SETTINGS:
       return "SEND_SETTINGS";
+    case GRPC_CHTTP2_INITIATE_WRITE_SETTINGS_ACK:
+      return "SETTINGS_ACK";
     case GRPC_CHTTP2_INITIATE_WRITE_FLOW_CONTROL_UNSTALLED_BY_SETTING:
       return "FLOW_CONTROL_UNSTALLED_BY_SETTING";
     case GRPC_CHTTP2_INITIATE_WRITE_FLOW_CONTROL_UNSTALLED_BY_UPDATE:

src/core/ext/transport/chttp2/transport/frame_settings.cc

@@ -151,6 +151,8 @@ grpc_error_handle grpc_chttp2_settings_parser_parse(void* p,
                    GRPC_CHTTP2_NUM_SETTINGS * sizeof(uint32_t));
             t->num_pending_induced_frames++;
             grpc_slice_buffer_add(&t->qbuf, grpc_chttp2_settings_ack_create());
+            grpc_chttp2_initiate_write(t,
+                                       GRPC_CHTTP2_INITIATE_WRITE_SETTINGS_ACK);
             if (t->notify_on_receive_settings != nullptr) {
               grpc_core::ExecCtx::Run(DEBUG_LOCATION,
                                       t->notify_on_receive_settings,

src/core/ext/transport/chttp2/transport/internal.h

@@ -98,6 +98,7 @@ typedef enum {
   GRPC_CHTTP2_INITIATE_WRITE_STREAM_FLOW_CONTROL,
   GRPC_CHTTP2_INITIATE_WRITE_TRANSPORT_FLOW_CONTROL,
   GRPC_CHTTP2_INITIATE_WRITE_SEND_SETTINGS,
+  GRPC_CHTTP2_INITIATE_WRITE_SETTINGS_ACK,
   GRPC_CHTTP2_INITIATE_WRITE_FLOW_CONTROL_UNSTALLED_BY_SETTING,
   GRPC_CHTTP2_INITIATE_WRITE_FLOW_CONTROL_UNSTALLED_BY_UPDATE,
   GRPC_CHTTP2_INITIATE_WRITE_APPLICATION_PING,

src/core/lib/debug/stats_data.cc

@@ -73,6 +73,7 @@ const char* grpc_stats_counter_name[GRPC_STATS_COUNTER_COUNT] = {
     "http2_initiate_write_due_to_stream_flow_control",
     "http2_initiate_write_due_to_transport_flow_control",
     "http2_initiate_write_due_to_send_settings",
+    "http2_initiate_write_due_to_settings_ack",
     "http2_initiate_write_due_to_bdp_estimator_ping",
     "http2_initiate_write_due_to_flow_control_unstalled_by_setting",
     "http2_initiate_write_due_to_flow_control_unstalled_by_update",
@@ -181,6 +182,7 @@ const char* grpc_stats_counter_doc[GRPC_STATS_COUNTER_COUNT] = {
     "Number of HTTP2 writes initiated due to 'stream_flow_control'",
     "Number of HTTP2 writes initiated due to 'transport_flow_control'",
     "Number of HTTP2 writes initiated due to 'send_settings'",
+    "Number of HTTP2 writes initiated due to 'settings_ack'",
     "Number of HTTP2 writes initiated due to 'bdp_estimator_ping'",
     "Number of HTTP2 writes initiated due to "
     "'flow_control_unstalled_by_setting'",

src/core/lib/debug/stats_data.h

@@ -74,6 +74,7 @@ typedef enum {
   GRPC_STATS_COUNTER_HTTP2_INITIATE_WRITE_DUE_TO_STREAM_FLOW_CONTROL,
   GRPC_STATS_COUNTER_HTTP2_INITIATE_WRITE_DUE_TO_TRANSPORT_FLOW_CONTROL,
   GRPC_STATS_COUNTER_HTTP2_INITIATE_WRITE_DUE_TO_SEND_SETTINGS,
+  GRPC_STATS_COUNTER_HTTP2_INITIATE_WRITE_DUE_TO_SETTINGS_ACK,
   GRPC_STATS_COUNTER_HTTP2_INITIATE_WRITE_DUE_TO_BDP_ESTIMATOR_PING,
   GRPC_STATS_COUNTER_HTTP2_INITIATE_WRITE_DUE_TO_FLOW_CONTROL_UNSTALLED_BY_SETTING,
   GRPC_STATS_COUNTER_HTTP2_INITIATE_WRITE_DUE_TO_FLOW_CONTROL_UNSTALLED_BY_UPDATE,
@@ -281,6 +282,9 @@ typedef enum {
 #define GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_SEND_SETTINGS() \
   GRPC_STATS_INC_COUNTER(                                          \
       GRPC_STATS_COUNTER_HTTP2_INITIATE_WRITE_DUE_TO_SEND_SETTINGS)
+#define GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_SETTINGS_ACK() \
+  GRPC_STATS_INC_COUNTER(                                         \
+      GRPC_STATS_COUNTER_HTTP2_INITIATE_WRITE_DUE_TO_SETTINGS_ACK)
 #define GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_BDP_ESTIMATOR_PING() \
   GRPC_STATS_INC_COUNTER(                                               \
       GRPC_STATS_COUNTER_HTTP2_INITIATE_WRITE_DUE_TO_BDP_ESTIMATOR_PING)
@@ -476,6 +480,7 @@ void grpc_stats_inc_server_cqs_checked(int x);
 #define GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_STREAM_FLOW_CONTROL()
 #define GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_TRANSPORT_FLOW_CONTROL()
 #define GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_SEND_SETTINGS()
+#define GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_SETTINGS_ACK()
 #define GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_BDP_ESTIMATOR_PING()
 #define GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_FLOW_CONTROL_UNSTALLED_BY_SETTING()
 #define GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_FLOW_CONTROL_UNSTALLED_BY_UPDATE()

src/core/lib/debug/stats_data.yaml

@@ -173,6 +173,8 @@
   doc: Number of HTTP2 writes initiated due to 'transport_flow_control'
 - counter: http2_initiate_write_due_to_send_settings
   doc: Number of HTTP2 writes initiated due to 'send_settings'
+- counter: http2_initiate_write_due_to_settings_ack
+  doc: Number of HTTP2 writes initiated due to 'settings_ack'
 - counter: http2_initiate_write_due_to_bdp_estimator_ping
   doc: Number of HTTP2 writes initiated due to 'bdp_estimator_ping'
 - counter: http2_initiate_write_due_to_flow_control_unstalled_by_setting

src/core/lib/debug/stats_data_bq_schema.sql

@@ -44,6 +44,7 @@ http2_initiate_write_due_to_close_from_api_per_iteration:FLOAT,
 http2_initiate_write_due_to_stream_flow_control_per_iteration:FLOAT,
 http2_initiate_write_due_to_transport_flow_control_per_iteration:FLOAT,
 http2_initiate_write_due_to_send_settings_per_iteration:FLOAT,
+http2_initiate_write_due_to_settings_ack_per_iteration:FLOAT,
 http2_initiate_write_due_to_bdp_estimator_ping_per_iteration:FLOAT,
 http2_initiate_write_due_to_flow_control_unstalled_by_setting_per_iteration:FLOAT,
 http2_initiate_write_due_to_flow_control_unstalled_by_update_per_iteration:FLOAT,

test/core/bad_client/bad_client.cc

@@ -282,9 +282,12 @@ grpc_bad_client_arg connection_preface_arg = {
 
 bool rst_stream_client_validator(grpc_slice_buffer* incoming, void* /*arg*/) {
   // Get last frame from incoming slice buffer.
+  constexpr int kExpectedFrameLength = 13;
+  if (incoming->length < kExpectedFrameLength) return false;
   grpc_slice_buffer last_frame_buffer;
   grpc_slice_buffer_init(&last_frame_buffer);
-  grpc_slice_buffer_trim_end(incoming, 13, &last_frame_buffer);
+  grpc_slice_buffer_trim_end(incoming, kExpectedFrameLength,
+                             &last_frame_buffer);
   GPR_ASSERT(last_frame_buffer.count == 1);
   grpc_slice last_frame = last_frame_buffer.slices[0];
 

tools/run_tests/performance/massage_qps_stats.py

@@ -157,6 +157,9 @@ def massage_qps_stats(scenario_result):
             stats[
                 "core_http2_initiate_write_due_to_send_settings"] = massage_qps_stats_helpers.counter(
                     core_stats, "http2_initiate_write_due_to_send_settings")
+            stats[
+                "core_http2_initiate_write_due_to_settings_ack"] = massage_qps_stats_helpers.counter(
+                    core_stats, "http2_initiate_write_due_to_settings_ack")
             stats[
                 "core_http2_initiate_write_due_to_bdp_estimator_ping"] = massage_qps_stats_helpers.counter(
                     core_stats,

tools/run_tests/performance/scenario_result_schema.json

@@ -340,6 +340,11 @@
         "name": "core_http2_initiate_write_due_to_send_settings",
         "type": "INTEGER"
       },
+      {
+        "mode": "NULLABLE",
+        "name": "core_http2_initiate_write_due_to_settings_ack",
+        "type": "INTEGER"
+      },
       {
         "mode": "NULLABLE",
         "name": "core_http2_initiate_write_due_to_bdp_estimator_ping",
@@ -1172,6 +1177,11 @@
         "name": "core_http2_initiate_write_due_to_send_settings",
         "type": "INTEGER"
       },
+      {
+        "mode": "NULLABLE",
+        "name": "core_http2_initiate_write_due_to_settings_ack",
+        "type": "INTEGER"
+      },
       {
         "mode": "NULLABLE",
         "name": "core_http2_initiate_write_due_to_bdp_estimator_ping",